Yesterday was the last day of New York Fashion Week, which looks from the sidelines to have delivered the usual mix of high glamour and drama. Fashion Weeks the world over, whether in Paris, London, Milan or the US, are all about being seen. Once design houses and individuals have showcased their collections for the upcoming year, pictures of models in the latest looks are shuttled over the globe, giving us a glimpse of trends for successive seasons. Some’ll have the wallet for the real thing, while others will have to wait until the high street interprets the clothes at more manageable price points.

Fashion gatherings lay bare the pull and power of dressing in our era. It’s clear for instance that it’s only partly about the clothes on the catwalk, with designers aiming to fill their front rows with famous faces, preferably dressing any personalities that attend. While a lot of this hoopla is far beyond our day-to-day experience of fashion, we do all get to read about some singer causing a stink in a series of outlandish outfits in Paris or the 14-your-old fashion blogger who sported a grey-rinse and sensible knits in New York. Whether we like it or not, it’s all proof of the potential of clothes to anger, enthuse or carry a message.

One artist at the NGA who understood the power of dressing was Agnolo di Cosimo, or Bronzino (1503 – 72). He was court painter for the Medici (the family who ruled Florence in the 15th and 16th centuries), doing mainly allegorical scenes and official portraits. In this picture, A Young Woman and Her Little Boy (c. 1540), a lady holds herself rigid in the sort of formal pose typical of members of the entourage of Cosimo I, Duke of Tuscany. Nestled at the left is a small blonde boy, who was added when Bronzino reworked this picture (X-radiography shows that she at first stood alone, with her right hand against her skirt).

Despite the straight gazes and open body-language here, this picture remains a mystery in as much as we don’t have a fixed idea of who the woman is. Beyond basic assumptions of her birth and social circle, it’s now largely her clothes that do the talking to us. Light enters from the left and brings her red dress alive: the ruches shine and the damask pattern meanders visibly. The fine golden material at the neckline is held in place by a single pearl. See the feathery lace at her wrists and fine inlaid rings on her fingers. The chains at the neck, breast and waist fall in concentric swags.

Even if this woman’s identity were known, the garments would still form a central part of the picture. The colors (a green background enriches the red further), patterns, textures and shapes all suggest wealth and womanly status and Bronzino’s analytical, clinical style lends itself perfectly to picking out the intricacies of these clothes. Would it surprise you to discover that the artist actually updated this lady’s wardrobe when he worked on the painting a second time? He enlarged and embellished her headdress, puffed her sleeves, gave her gloves and put in the pattern on her bodice. Bronzino was an artist aware of the power of dressing in his context, so much so that his works may even have affected the way women wanted to look at court, inspired by the lavish clothes, stiff stance and haughty expression we see here. Florentine fashion trend-setting at its finest, it would seem.